Background Information
Causes
Most common cause: parainfluenza
Risk Factors
- 6 months – 3 y/o (peak age group affected)
- Male
- Previous intubation
Clinical Features
- Initial prodromal phase
- Followed by sudden onset of subglottic oedema/narrowing manifesting as:
- Seal-like barking cough – characteristic feature
- Stridor
- Hoarseness
- Dyspnoea
Symptoms typically worsen or manifest at night and increase with agitation.
When examining a child with croup:
- Do not frighten the children
- Ensure the child is seated comfortably in the parent / carer’s lap
- Do not attempt to reposition the child (as the naturally adopted position minimises airway obstruction)
If epiglottitis is suspected, do NOT examine the oropharynx as it may precipitate further airway obstruction.
Severity Classification
| Severity | Features |
|---|---|
| Mild |
|
| Moderate |
|
| Severe |
|
| Impending respiratory failure |
|
Diagnosis Guidelines
Investigation and Diagnosis
Croup is diagnosed clinically (see above for clinical features).
The characteristic X-ray finding is the steeple signRefers to the tapering of the subglottic tracheal air column, resembling the shape of a church steeple, caused by mucosal edema and narrowing of the subglottic region.
This sign is considered characteristic of croup but is not universally present; its absence does not exclude the diagnosis, and its presence is not pathognomonic, as mild cases may have normal imaging and other causes of upper airway obstruction can produce similar findings. Note that the steeple sign is NOT specific to croup, but simply indicative of subglottic narrowing (other causes include epiglottitis, tracheitis)
Clinically, investigations are not routinely performed but this is important for exams.
Management Guidelines
Admission Criteria
Admit all children with moderate/severe croup
- Mild croup does NOT require admission and can be managed on outpatient basis
Consider hospital admission if:
- Respiratory rate >60 / min
- High fever
- ‘Toxic’ appearance
- Mild croup with risk factors (chronic lung disease / haemodynamically significant congenital heart disease / neuromuscular disorders / immunodeficiency / <3 months / inadequate fluid intake / long-distance to healthcare)
Management
Give a single dose of corticosteroid immediately to ALL patients (all severities)
- 1st line typically: oral dexamethasone (0.15 mg/kg), oral prednisolone (1–2 mg/kg) also appropriate
- If the child is too ill to take oral medication → nebulised budesonide / IM dexamethasone
In severe croup / impending respiratory failure:
- Give controlled supplementary oxygen
- If not controlled with corticosteroid → nebulised adrenaline